Process for preparing photoactive coumarin derivatives

ABSTRACT

Novel processes for the preparation of a new class of coumarin derivatives, which are useful as photoactive compounds in a wide variety of applications including photoresists and other opto-electronic applications, are disclosed and claimed. The process involves a multi-step synthetic method for the preparation of ether, ester, carbonate, or sulfonate derivative of 5-hydroxy, 6-hydroxy, or 7-hydroxy-3-diazo-4-oxo-3,4-dihydrocoumarin starting from the corresponding dihydroxyacetophenone. The compounds formed from the process of the present invention exhibit very high photosensitivity in the deep ultraviolet (DUV) region (ca. 250 nm), and therefore, are useful as photoactive compounds in DUV photoresist formulations.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a unique, novel, and cost effectiveprocess for preparing ethers, carboxylic acid and sulfonic acid esters,and carbonates of 3-diazo-2,4-dioxo-benzo-heterocyclic compounds such as3-diazo-3,4-dihydrocoumarins, which are useful synthetic intermediatesin a wide variety of applications including photoresists,opto-electronics, agricultural, and pharmaceutical applications. Morespecifically, the present invention relates to a process for preparingethers, carboxylic acid and sulfonic acid esters, and carbonates of3-diazo-4-oxo-3,4-dihydrocoumarins which are useful as photoactivecompounds in the photoresist formulations having applications in thedeep ultraviolet region.

2. Description of the Prior Art

It is well-known that diazo compounds are used as"photoactive-compounds" (PACs) in photoresist formulations. For example,diazonaphthoquinones (DNQs) are widely used as PACs in positivephotoresist formulations. The DNQs, for example, contain a wide varietyof ballast groups which can be tailored to adjust the solubility of DNQsbefore and after exposure to actinic radiation such as ultraviolet inthe 360-450 nm region. The DNQs also undergo photochemicaltransformation when exposed to actinic radiation. Furthermore, when DNQsare blended with phenolic resins, they tend to promote the solubility ofthe phenolic resins after exposure to radiation. The unexposed DNQshaving the ballast groups on the other hand inhibits dissolution of thephenolic resins. As a result, fine patterns (lines) can be formed usingappropriate photomasks and actinic radiation sources, and such patternsare useful in semiconductor/microelectronics industry.

As mentioned above, the commercially used photoresists containing theDNQs are frequently used in the 360-450 nm region of the electromagneticspectrum. However, the current trend in the electronic industry is todevelop semiconductor devices having extremely fine patterns. In orderto obtain such fine patterns there is a need to develop photoresistformulation that can be developed in the 240-260 nm (i.e., the deepultraviolet, DUV, region).

However, the currently commercially used DNQs, after exposure to light,absorb strongly between 240-260 nm region, and therefore, preclude theiruse as PACs in the DUV photoresist formulations. Therefore, it is anobject of this invention to provide novel PACs which have no or minimalabsorptions in the DUV region and thus are useful in DUV photoresistformulations. It is also an objective of this invention to provide acost-effective, economic process for the preparation of the novel PACsof this invention.

PRIOR ART

The following references are disclosed as background prior art.

U.S. Pat. No. 4,211,791 discloses novel substituted coumarins andindanediones and a process for preparing them.

U.S. Pat. No. 4,339,522 discloses an ultraviolet lithographic resistcomposition and a process of making such composition which containsphenolic-aldehyde resins sensitized with Meldrum's diazo or a homologuethereof.

U.S. Pat. No. 4,588,670 discloses a light sensitive triester ofo-quinone diazide containing positive photoresist compositions.

U.S. Pat. No. 4,853,315 describes o-quinone diazide sulfonic acidmonoesters useful as sensitizers for positive resists. The esters of1-oxo-2-diazo-naphthalene sulfonic acid in which the sulfonic acid groupis either at 4- or the 5- position of a 3 (or 4)-hydroxymethyl-tricyclo5.2.1.0.²,6 !decane are useful as sensitizers for positive resists,particularly at 365 nm.

U.S. Pat. No. 4,942,225 describes preparation of diazo and azo compoundsusing azidoformamidium salts.

U.S. Pat. No. 5,501,936 discloses positive-working quinonediazidephotoresist composition containing a cyclohexyl-substitutedtriphenylmethane compound which is capable of giving an extremely finepatterned resist layer.

U.S. Pat. No. 5,532,107 describes positive resist composition containingphotosensitive agents, which are quinonediazide sulfonates of tris- ortetra-hydroxy derivatives of triphenyl alkanes.

U.S. Pat. No. 5,541,033 discloses o-quinonediazide sulfonic acid estersof phenolic compounds and their use in radiation-sensitive compositions.

Japanese Laid-open Pat. No. Heisei 2-61640 discloses photosensitivecompositions comprising an alkali-soluble resin and a photosensitizerhaving a 2-diazo-1,3-diketo group. Specific photosensitizer compoundsincluded monosubstituted 3-diazo-4-oxo-3,4-dihydrocoumarins (examples ofsubstituents included 7-methyl, 7-propyl, 7-methoxy, and 6-chloro).However, only the unsubstituted 3-diazo-4-oxo-3,4-dihydrocoumarin wasused in the photoresist formulation.

Japanese Laid-open Pat. No. Heisei 3-79670 discloses a negative-typeradiation sensitive resin composition containing radiation sensitivematerials having a diazo keto group. Specific examples of radiationsensitive materials included substituted indanones, tetralones,tetrahydronaphthadiones, tetrahydroquinolones, and chromanones.Unsubstituted 3-diazo-4-oxo-3,4-dihydrocoumarin was also used asradiation sensitive material in this disclosure.

J. Med. Chem. 1971, Vol. 14, (pp. 167-168) describe the synthesis of4,5-, 4,6-, or 4,7-dihydroxy coumarins.

All of the references described herein are incorporated herein byreference in their entirety.

SUMMARY OF THE INVENTION

Surprisingly, the present invention provides a novel class of compoundswhich can function effectively as PACs in the DUV region. The compoundsof the present invention are ethers, carboxylic acid and sulfonic acidesters, and carbonates of 3-diazo-2,4-dioxo-benzo-heterocyclic compoundshaving the formula: ##STR1## wherein: (a) X is either oxygen or sulfur;

(b) R is selected from the group consisting of:

hydrogen,

alkyl of valence n having 1 to 16 carbon atoms,

aralkyl of valence n having 7 to 24 carbon atoms,

aryl of valence n having 6 to 24 carbon atoms,

acyl group having the formula, R'--(CO)_(n) --, where R' is an aliphaticor aromatic group of valence n having 1 to 24 carbon atoms, and n is aninteger having a value of 1 to 10,

alkoxy or aryloxy carbonyl having the formula, R'--(O--CO)_(n) --, whereR' is an aliphatic or aromatic group of valence n having 1 to 24 carbonatoms, and

sulfonylakyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --, whereR' is an aliphatic or aromatic group of valence n having 1 to 24 carbonatoms;

(c) R₁, R₂, and R₃ are the same or different and are independentlyselected from the group consisting of:

hydrogen,

fluorine, chlorine, bromine, or iodine,

linear or branched alkyl and fluoroalkyl groups having the formula C_(q)H_(x) F_(y),

where q is an integer from 1 to 8, x and y are integers from 0 to 2q+1,and the sum of x and y is 2q+1;,

aryl having 6 to 10 carbon atoms,

aralkyl having 7 to 10 carbon atoms,

alkoxy having 1 to 8 carbon atoms,

aryloxy having 6 to 10 carbon atoms, and

aralkyloxy having 7 to 10 carbon atoms; and

(d) n is an integer having a value of 1 to 10.

In another aspect, this invention also provides a process for thepreparation of the novel ethers, carboxylic acid and sulfonic acidesters, and carbonates of 5-, 6-, or7-(3-diazo-2,4-dioxo-benzo-heterocyclic compounds) of the presentinvention. Thus, the process for preparing the novel ethers, carboxylicacid and sulfonic acid esters, and carbonates of3-diazo-2,4-dioxo-benzo-heterocyclic compounds involves the steps of:

(a) subjecting a substituted hydroxy acetophenone to a substitutionreaction in the presence of a suitable protecting group for a sufficientperiod of time and under suitable conditions of temperature and pressureto form the corresponding hydroxy-protected-acetophenone;

(b) subjecting said hydroxy-protected-acetophenone to suitableaddition-cyclization conditions in the presence of a dialkyl carbonateand a catalyst for a sufficient period of time and under suitableconditions of temperature and pressure to form the correspondingbenzo-heterocyclic compound containing a β-keto-enol group;

(c) subjecting said heterocyclic compound to suitable deprotectionconditions for a sufficient period of time and under suitable conditionsof temperature and pressure to form the correspondinghydroxy-benzo-heterocyclic compound containing a β-keto-enol group;

(d) subjecting said hydroxy-benzo-heterocyclic compound to suitablesubstitution conditions in the presence of a compound having theformula:

    R--Z.sub.n,

where

(i) Z is chlorine or bromine;

(ii) n is an integer having a value of 1 to 10; and

(iii) R is selected from the group consisting of:

alkyl of valence n having 1 to 16 carbon atoms,

aralkyl of valence n having 7 to 24 carbon atoms,

aryl of valence n having 6 to 24 carbon atoms,

acyl group having the formula, R'--(CO)_(n) --, where R' is an aliphaticor aromatic group of valence n having 1 to 24 carbon atoms,

alkoxy or aryloxy carbonyl having the formula, R'--(O--CO)_(n) --, whereR' is an aliphatic or aromatic group of valence n having 1 to 24 carbonatoms, and

sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 24carbon atoms; for a sufficient period of time and under suitableconditions of temperature and pressure to form the corresponding ether,carboxylic acid or sulfonic acid ester, or carbonate ofbenzo-heterocyclic compound containing a β-keto-enol group; and

(e) subjecting said β-keto-enol compound from step (d) to suitable diazotransfer conditions in the presence of a diazo transfer agent for asufficient period of time and under suitable conditions of temperatureand pressure to form the corresponding ether, carboxylic acid orsulfonic acid ester, or carbonate of3-diazo-2,4-dioxo-benzo-heterocyclic compound.

DETAILED DESCRIPTION OF THE INVENTION

Unexpectedly and surprisingly, it has now been found that ethers,carboxylic acid and sulfonic acid esters, and carbonates of3-diazo-2,4-dioxo-benzo-heterocyclic compounds of the present inventionexhibit low or no absorptions in the deep ultraviolet region (DUV),after exposure to DUV light. In addition, a wide variety of derivativesof these novel compounds can be readily made using a cost-effective,economic process as described herein. Thus, these compounds find utilityas photoactive-compounds (PACs) in the DUV photoresist formulations.

The compounds of the present invention have the formula: ##STR2##wherein: (a) X is either oxygen or sulfur;

(b) R is selected from the group consisting of:

hydrogen,

alkyl of valence n having 1 to 16 carbon atoms,

aralkyl of valence n having 7 to 24 carbon atoms,

aryl of valence n having 6 to 24 carbon atoms,

acyl group having the formula, R'--(CO)_(n) --, where R' is an aliphaticor aromatic group of valence n having 1 to 24 carbon atoms,

alkoxy or aryloxy carbonyl having the formula, R'--(O--CO)_(n) --, whereR' is an aliphatic or aromatic group of valence n having 1 to 24 carbonatoms, and

sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 24carbon atoms;

(c) R₁, R₂, and R₃ are the same or different and are independentlyselected from the group consisting of:

hydrogen,

fluorine, chlorine, bromine, or iodine,

linear or branched alkyl and fluoroalkyl groups having the formula C_(q)H_(x) F_(y), where q is an integer from 1 to 8, x and y are integersfrom 0 to 2q+1, and the sum of x and y is 2q+1;

aryl having 6 to 10 carbon atoms,

aralkyl having 7 to 10 carbon atoms,

alkoxy having 1 to 8 carbon atoms,

aryloxy having 6 to 10 carbon atoms, and

aralkyloxy having 7 to 10 carbon atoms; and

(d) n is an integer having a value of 1 to 10.

In the above definitions and throughout the present specification, alkylmeans linear or branched alkyl having desirable number of carbon atomsand valence. Thus, a suitable R as specified herein may be a alkyl groupof valence n having 1 to 16 carbon atoms, where n is an integer having avalue of 1 to 10. The alkyl group is also often called as aliphaticgroup and may be acyclic (i.e., non-cyclic) or cyclic. Thus, suitableacyclic alkyl groups of valence 1 include methyl, ethyl, n- oriso-propyl, n-, iso-, or tert-butyl, linear or branched pentyl, hexyl,octyl, decyl, dodecyl, tetradecyl, and hexadecyl. The cyclic alkylgroups may be monocyclic or polycyclic. Suitable example of mono-cyclicalkyl groups include substituted cyclopentyl, cyclohexyl, andcycloheptyl groups. The substituents may be any of the acyclic alkylgroups described herein.

Suitable bicyclic alkyl groups include substituted bicyclo2.2.1!heptane, bicyclo 2.2.2!octane, bicyclo 3.2.1!octane, bicyclo3.2.2!nonane, and bicyclo 3.3.2!decane, and the like. Examples oftricyclic alkyl groups include tricyclo 5.4.0.0.²,9 !undecane, tricyclo4.2.1.2.⁷,9 !undecane, tricyclo 5.3.2.0.⁴,9 !dodecane, and tricyclo5.2.1.0.²,6 !decane. As mentioned herein the cyclic alkyl groups mayhave any of the acyclic alkyl groups as substituents.

The multivalent alkyl groups are derived from any of the alkyl groupsmentioned hereinabove. Accordingly, a divalent acyclic group may bemethylene, 1,1- or 1,2-ethylene, 1,1-, 1,2-, or 1,3 propylene and so on.Similarly, a divalent cyclic alkyl group may be 1,2- or1,3-cyclopentylene, 1,2-, 1,3-, or 1,4-cyclohexylene, and the like. Adivalent tricyclo alkyl groups may be any of the tricyclic alkyl groupsmentioned herein above. A particularly useful tricyclic alkyl group inthis invention is 4,8-bis(methylene)-tricyclo 5.2.1.0.²,6 !decane.

Suitable examples of monovalent aryl group having 6 to 24 carbon atomsinclude phenyl, tolyl, xylyl, naphthyl, biphenyls, bis-phenyls,tris-phenyls and the like. These aryl groups may further be substitutedwith any of the appropriate alkyl or aryl groups mentioned hereinabove.Similarly, appropriate polyvalent aryl groups as desired may be used inthis invention. Representative examples of divalent aryl groups includephenylenes, xylylenes, naphthylenes, biphenylenes, and the like.

Representative examples of monovalent aralkyl having 7 to 24 carbonatoms include phenylmethyl, phenylethyl, diphenylmethyl, 1,1- or1,2-diphenylethyl, 1,1-, 1,2-, 2,2-, or 1,3-diphenylpropyl, and thelike. Appropriate combinations of substituted aralkyl groups asdescribed herein having desirable valence may be used as a polyvalentaralkyl group.

Suitable alkyl, aryl or aralkyl substituents as R₁, R₂, and R₃ may bethe same as described herein. Representative examples of linear orbranched fluoroalkyl groups having 1 to 8 carbon atoms include, forexample, trifluoromethyl, 1,1,2-trifluoroethyl, pentafluoroethyl,perfluoropropyl, perfluorobutyl, and 1,1,2,3,3-pentafluorobutyl.

As used herein, alkoxy means straight or branched chain alkoxy having 1to 10 carbon atoms, and includes, for example, methoxy, ethoxy,n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, pentyloxy,hexyloxy, heptyloxy, octyloxy, nonanyloxy, decanyloxy, 4-methylhexyloxy,2-propylheptyloxy, and 2-ethyloctyloxy.

Examples of aryloxy having 6 to 10 carbon atoms may include phenoxy,tolyloxy, xylyloxy, and the like. Examples of aralkyloxy having 7 to 10carbon atoms include phenylmethoxy, α- or β-phenethyloxy,2-phenylpropyloxy, and the like.

Suitable examples of monovalent aliphatic acyclic acyl groups includeacetyl, propionyl, n- or iso-butyryl, valeroyl, hexanoyl, octanoyl,dodecanoyl, strearyl, and the like. Examples of divalent aliphaticacyclic acyl groups include oxalyl, malonyl, succinoyl, glutaroyl,adipoyl, and the like. Suitable examples of aliphatic cyclic acyl groupsinclude α-cyclopentylacetyl, α-cyclohexylacetyl, α-cycloheptylacetyl,β-cyclopentylpropionyl, and the like. Examples of divalent aliphaticcyclic acyl groups include 1,4-cyclohexane-dicarboxyl,1,3-cyclohexane-dicarboxyl, and the like. Similarly, a wide variety ofwell known bicyclic and polycyclic acyl groups may be employed in thisinvention. A particularly useful tricyclic acyl group is4,8-bis(carboxyl)tricyclo 5.2.1.0²,6 !decane.

The sulfonylalkyl or sulfonylaryl referred to herein may be derived fromany of the alkyl, aryl, aralkyl groups described herein. As arepresentative example, without any limitation, methanesulfonyl,ethanesulfonyl, cyclohexanesulfonyl, benzenesulfonyl, p-toluenesulfonyl,and 4,4'-bis(sulfonylphenyl)ether may be enumerated.

Furthermore, and as used herein, the term "substituted" is contemplatedto include all permissible substituents of organic compounds. In a broadaspect, the permissible substituents include acyclic and cyclic,branched and unbranched, carbocyclic and heterocyclic, aromatic andnon-aromatic substituents of organic compounds. Illustrativesubstituents include, for example, those described hereinabove. Thepermissible substituents can be one or more and the same or differentfor appropriate organic compounds. For purposes of this invention, theheteroatoms such as nitrogen may have hydrogen substituents and/or anypermissible substituents of organic compounds described herein whichsatisfy the valencies of the heteroatoms. This invention is not intendedto be limited in any manner by the permissible substituents of organiccompounds.

In another embodiment of this invention, the R group used to prepare theether, carboxylic acid or sulfonic acid ester, or a carbonate of thepresent invention functions as a ballast group. As described herein, aballast group is intended to mean a wide variety of alkyl, aryl, oraralkyl groups of desirable valence as described hereinabove. Any of theballast groups well known in the art may be used. A number of differentballast groups are described in U.S. Pat. No. 4,588,670; U.S. Pat. No.4,853,315; U.S. Pat. No. 5,501,936; and U.S. Pat. No. 5,532,107; all ofwhich are incorporated herein by reference in their entirety.

It is believed that judicious selection of the ballast group isextremely critical to obtain desired intended benefit from the3,4-dihydrocoumarin compound. The ballast group plays several rolesparticularly if it is used in the photoresist formulation. It isbelieved that the appropriate selection of ballast group can affect thesolubility of the photoresist formulation formed therefrom. The ballastgroup further affects the shelf/formulation stability as well as thethermal stability of the photoresist formulation.

Particularly preferred compounds of this invention are those in which R₁to R₃ are unsubstituted, i.e., in these compounds R₁ to R₃ are hydrogen.Also, the preferred compounds of this invention are 3,4-dihydrocoumarinderivatives, i.e., X is oxygen, and R is hydrogen. Specific examples ofthe preferred compounds of this type are as mentioned below:

3-diazo-4-oxo-5-hydroxy-3,4-dihydrocoumarin, Formula 1;

3-diazo-4-oxo-6-hydroxy-3,4-dihydrocoumarin, Formula 2; and

3-diazo-4-oxo-7-hydroxy-3,4-dihydrocoumarin, Formula 3. ##STR3##

In another embodiment of this invention, the ether, carboxylic acid andsulfonic acid esters, and carbonates of substituted3-diazo-4-oxo-3,4-dihydrocoumarin are the preferred compounds.Particulaly preferred compounds are unsubstituted, i.e., in which R₁ toR₃ are hydrogen.

Specific examples of ethers of 3-diazo-4-oxo-3,4-dihydrocoumarin are3-diazo-4-oxo-6-benzyloxy-3,4-dihydrocoumarin (Formula 4); and4,8-bis(3-diazo-4-oxo-6-oxymethyl-3,4-dihydrocoumarin)tricyclo5.2.1.0..sup.2,6 !decane (Formula 5) as shown below. ##STR4##

Specific examples of carboxylic acid esters of3-diazo-4-oxo-3,4-dihydro-coumarin are as mentioned below:

4,8-bis(3-diazo-4-oxo-6-oxycarbonyl-3,4-dihydrocoumarin)tricyclo5.2.1.0..sup.2,6 !decane, Formula 6. ##STR5##

Specific examples of carbonate esters of3-diazo-4-oxo-3,4-dihydrocoumarin are as mentioned below:

1',1',1'-tris-4-(3-diazo-4-oxo-3,4-dihydrocoumarin-6-carbonatophenyl)ethane,Formula 7; ##STR6##4,8-bis(3-diazo-4-oxo-3,4-dihydrocoumarin-6-formate)tricyclo5.2.1.0..sup.2,6 !decane, Formula 8, ##STR7##

Specific examples of sulfonate esters of3-diazo-4-oxo-3,4-dihydrocoumarin are as mentioned below:

4,4'-bis(3-diazo-4-oxo-6-oxysulfonylphenyl-3,4-dihydrocoumarin)ether,Formula 9 ##STR8##

In another facet of this invention there is also provided a novel,unique, and efficient process for preparing the novel ethers, carboxylicacid and sulfonic acid esters, and carbonates of3-diazo-2,4-dioxo-benzo-heterocyclic compounds comprising the steps of:

(a) subjecting a substituted hydroxy acetophenone to a substitutionreaction in the presence of a suitable protecting group for a sufficientperiod of time and under suitable conditions of temperature and pressureto form the corresponding hydroxy-protected-acetophenone;

(b) subjecting said hydroxy-protected-acetophenone to suitablecondensation-cyclization conditions in the presence of a dialkylcarbonate and a catalyst for a sufficient period of time and undersuitable conditions of temperature and pressure to form thecorresponding benzo-heterocyclic compound containing a β-keto-enolgroup;

(c) subjecting said heterocyclic compound to suitable deprotectionconditions for a sufficient period of time and under suitable conditionsof temperature and pressure to form the correspondinghydroxy-benzo-heterocyclic compound containing a β-keto-enol group;

(d) subjecting said hydroxy-benzo-heterocyclic compound to suitablesubstitution conditions in the presence of a compound having theformula:

    R--Z.sub.n,

where

(i) Z is chlorine or bromine;

(ii) n is an integer having a value of 1 to 10; and

(iii) R is selected from the group consisting of:

alkyl of valence n having 1 to 16 carbon atoms,

aralkyl of valence n having 7 to 24 carbon atoms,

aryl of valence n having 6 to 24 carbon atoms,

acyl group having the formula, R'--(CO)_(n) --, where R' is an aliphaticor aromatic group of valence n having 1 to 24 carbon atoms,

alkoxy or aryloxy carbonyl having the formula, R'--(O--CO)_(n) --, whereR' is an aliphatic or aromatic group of valence n having 1 to 24 carbonatoms, and

sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 24carbon atoms;

for a sufficient period of time and under suitable conditions oftemperature and pressure to form the corresponding ether, carboxylicacid or sulfonic acid ester, or carbonate of benzo-heterocyclic compoundcontaining a β-keto-enol group; and

(e) subjecting said β-keto-enol compound from step (d) to suitable diazotransfer conditions in the presence of a diazo transfer agent for asufficient period of time and under suitable conditions of temperatureand pressure to form the corresponding ether, carboxylic acid orsulfonic acid ester, or carbonate of3-diazo-2,4-dioxo-benzo-heterocyclic compound.

The starting material, i.e., the substituted hydroxy acetophenone hasthe formula, I as shown below: ##STR9## where R₁, R₂, R₃, and X are asdefined above.

Utilizing the substituted hydroxy acetophenone (Formula I), it isbelieved that the process of the present invention proceeds as shown inScheme I below: ##STR10##

In Scheme I, steps (a) through (e) correspond to those steps (a) through(e) mentioned herein. In Scheme I, substituents R, R₁, R₂, R₃, X, and nare as defined above. The PrO-- substituent in Formulae II and III is aprotecting group for the phenolic hydroxy group as mentioned herein,which is described in more detail below.

In step (a), the phenolic hydroxy group in the substituted hydroxyacetophenone, Formula I is protected by a suitable protecting groupusing any of the well known methods in the art. A wide variety ofprotecting groups may be employed in step (a) provided that theprotecting group is stable to the reactions conditions in step (b) ofthe process of the present invention. Suitable protecting groups forthis purpose include, without limitation, benzyl, trimethylsilyl,tert-butyldimethylsilyl, 2-tetrahydropyranyl, and tert-butyloxycarbonyl.The benzyl group is particularly preferred protecting group.

The desired protecting group may be introduced into the Formula I instep (a) by any of the well known methods in the art. For instance,benzyl group may be introduced by reaction of the starting material, Iwith benzyl chloride (halide) under suitable substitution reactionconditions. The amount of benzyl chloride used in step (a) is generallystoichiometric, i.e., one mole of benzyl chloride per mole of thestarting material, I. However, it is preferable that slight excess ofbenzyl chloride is employed in order to achieve complete conversion ofstarting material, I to the hydroxy-protected acetophenone, II.

In general, the substitution reaction in step (a) is carried out in thepresence of a base, particularly when benzyl chloride (halide) is usedin step (a). Any base may be used which will function for thesubstitution conditions to produce the desired end product, i.e.,hydroxy-protected acetophenone, Formula II in step (a) of the process ofthe present invention. Accordingly, a suitable base includes aninorganic base such as a metal hydroxide, preferably an alkali metalhydroxide, an alkali metal carbonate, e.g., K₂ CO₃ ; an alkali metalalkoxide (an ionic organic base), such as NaOCH₃, KOC(CH₃)₃, etc.; analkali metal organic salt (an ionic organic base) such as potassiumacetate, etc.; and an amine (a non-ionic organic base) such as pyridine,or a tri-lower-alkylamine, e.g., tripropylamine, trimethylamine,triethylamine, an hindered base such as 1,4-diazabicyclo 2.2.2!octane,and 4-dimethylaminopyridine, etc.

Additionally, suitable catalysts or co-catalysts may be used in step(a). Any material which accelerates or promotes the rate of substitutionreaction when used in small quantities may be used as catalysts orco-catalysts in step (a). For example, when benzyl chloride is used instep (a), small amounts of potassium iodide substantially acceleratesthe rate of substitution to form the benzyl-protected hydroxyacetophenone.

The temperature at which step (a) is conducted ranges from about 50° C.to about 180° C., preferably from about 60° C. to about 100° C. Thepressure in this step (a) is not critical and can be subatmospheric,atmospheric, or super atmospheric. The reaction times in step (a) willgenerally range from about 3 hours to about 12 hours or longer andsometimes under an inert atmosphere such as nitrogen or argon. Using theprocedure of step (a) outlined herein, the substituted hydroxyacetophenone (Formula I, Scheme I) undergoes suitable substitutionreaction to form the corresponding hydroxy protected acetophenone,Formula II, Scheme I.

In step (b), the hydroxy protected acetophenone, II is subjected tocondensation-cyclization reaction to form the correspondingbenzo-heterocyclic compound, Formula III, Scheme I. A description ofsuch condensation-cyclization reaction for the preparation ofhydroxy-coumarins may be found in U.S. Pat. No. 4,211,791 incorporatedherein by reference in its entirety.

Illustratively, the hydroxy protected acetophenone, II is reacted withdiethyl carbonate, preferably in the presence of a suitable base. It ispreferable that a strong base is employed in step (b) in order to obtainhigher yields of the heterocyclic product, Formula III, Scheme I.Accordingly, suitable base for this reaction include sodium amide,sodium hydride, or potassium hydride. The amount of base employed instep (b) is from about 0.5 to about 6 moles per mole of hydroxyprotected acetophenone, II. The preferred amount is from about 1 mole toabout 1.5 moles per mole of II.

The temperature at which step (b) is conducted ranges from about 80° C.to about 200° C., preferably from about 100° C. to about 150° C. Thepressure in this step (b) is not critical and can be subatmospheric,atmospheric, or super atmospheric. The reaction times in step (b) willgenerally range from about 4 hours to about 12 hours or longer andsometimes under an inert atmosphere such as nitrogen or argon. Using theprocedure of step (b) outlined herein, the hydroxy protectedacetophenone (Formula II, Scheme I) undergoes suitableaddition-cyclization reaction to form the corresponding heterocycliccompound, Formula III, Scheme I.

In step (c), the protecting group is deprotected under suitabledeprotection conditions to form the corresponding hydroxybenzo-heterocyclic compound, Formula IV, Scheme I. The conditionsemployed for the deprotection depends upon the type of protecting groupemployed. For instance, silyl groups or tetrahydropyranyl groups asdescribed herein may be deprotected using a variety of acidic reactionconditions well known in the art.

As mentioned herein, a particularly useful protecting group in thisinvention is benzyl group which can be deprotected by subjecting thecompound, III to hydrogenation conditions. Any suitable hydrogenationconditions known in the art may be used. For example, in this instanceit has been found that the compound, III undergoes hydrogenation readilyunder hydrogen pressure in the range of from about 75 psi to about 150psi over palladium catalyst. Various other catalysts such as platinumand supported metal catalysts may also be used. A particularly suitablecatalyst in step (c) is 5% palladium supported on carbon.

The temperature at which step (c) is conducted ranges from about 20° C.to about 80° C., preferably from about 40° C. to about 60° C. Thepressure in this step (c) is critical and generally super atmosphericpressures of from about 75 psi to about 150 psi is preferred or in aninert atmosphere such as nitrogen. The reaction times in step (c) willgenerally range from about 1 hour to about 8 hours or longer usually inan hydrogen atmosphere as described herein. Using the procedure of step(c) outlined herein, the substituted hydroxy-protected heterocycliccompound (Formula III, Scheme I) undergoes suitable deprotectionreaction to form the corresponding hydroxy heterocyclic compound,Formula IV, Scheme I.

In step (d), the compound, IV is subjected to suitable substitutionreaction with a wide variety of R--Z_(n) compounds as describedhereinabove. As mentioned hereinabove, the "R" group serves as a ballastgroup and appropriate selection of "R" group is critical in order toobtain the maximum benefit of the compound VI particularly as aphotoactive-compound.

Accordingly, depending upon the type of R--Z_(n) employed ethers,carboxylic acid or sulfonic acid esters, or carbonates of heterocycliccompound (Formula V, Scheme I) may be prepared. Thus, for instancereaction of compound IV with an alkyl, aryl, aralkyl halide results in aether, V; reaction of compound IV with an aliphatic or aromatic acylhalide of the formula, R'--(COZ)_(n), results in an ester, V, where R'is as defined above; reaction of compound IV with a suitablehaloformates of the formula, R'--(OCOZ)_(n) results in a carbonate, V;and reaction of compound IV with a suitable alkyl or arylsufonylhalideof the formula, R'--(SO₂ Z)_(n) results in a sulfonate, V.

The amounts of R--Z_(n) employed in step (d) depends upon the value ofn. For instance, if n=1, then one mole of R--Z_(n) per mole of compoundis employed. It is preferable that to obtain higher yields of compoundV, slight excess in the range of 10 to 20 mole percent excess ofR--Z_(n) is used. Similarly, if n>1, then the amount of compound IV usedis n moles of compound IV per mole of R--Z_(n). Sometimes it isadvantageous to employ less than the desired amounts of compound IV toobtain a compound which is partially substituted, i.e., in compound V,all of the functional groups of R--Z_(n) is not substituted withcompound IV.

In general in step (d), a base is also used. Suitable base in step (d)is the same base as used in step (a) as described hereinabove. Theorganic bases such as triethyl amine or hindered amine bases describedherein are particularly suitable bases in step (d).

The temperature at which step (d) is conducted ranges from about 10° C.to about 180° C., preferably from about 20° C. to about 40° C. Thepressure in this step (d) is not critical and can be sub atmospheric,atmospheric, or super atmospheric. The reaction times in step (d) willgenerally range from about 3 hours to about 12 hours or longer andsometimes under an inert atmosphere such as nitrogen or argon. Using theprocedure of step (d) outlined herein, the substitutedhydroxy-benzo-heterocyclic compound (Formula IV, Scheme I) undergoessuitable substitution reaction to form the corresponding ether,carboxylic acid or sulfonic acid ester, or carbonate of3-diazo-2,4-dioxo-benzo-heterocyclic compound, Formula V, Scheme I.

In step (e) the compound, V is finally subjected to diazo transferreaction to form the compound, VI, Scheme I. The diazo transfer reactioncan be carried out using any of the well known methods in the art. Forinstance, a description of a diazo transfer reaction may be found inU.S. Pat. No. 4,942,225 and in Org. Syn. Collective Vol. 5, pp 179-183;both of which are incorporated herein by reference in their entirety. Ithas now been found that p-toluenesulfonyl (tosyl) azide works aseffective diazo transfer agent to form the diazo compound VI as shown inScheme I.

The amount of tosyl azide used in step (e) is generally stoichiometricamount, i.e., one mole of azide per mole of the compound, V. It ispreferable that slight excess of tosyl azide is employed in order toachieve complete conversion of compound, V to the diazo compound VI. Itis also preferable that the reaction is carried out in the presence ofsuitable base. Examples of such base include triethylamine, pyridine,imidazole, and the like.

The temperature at which step (e) is conducted ranges from about 10° C.to about 50° C., preferably from about 20° C. to about 40° C. Thepressure in this step (e) is not critical and can be subatmospheric,atmospheric, or super atmospheric. The reaction times in step (e) willgenerally range from about 1/4 hour to about 4 hours or longer andsometimes under an inert atmosphere such as nitrogen or argon. Using theprocedure of step (e) outlined herein, the substitutedbenzo-heterocyclic β-keto-enol compound (Formula V, Scheme I) undergoessuitable diazo transfer reaction to form the corresponding3-diazo-2,4-dioxo-benzo-heterocyclic compound, Formula VI, Scheme I.

In one of the preferred embodiments of the process of this invention thepreferred compounds formed from the process of this invention areethers, carboxylic acid or sulfonic acid esters, and carbonates of3-diazo-4-oxo-3,4-dihydrocoumarins, i.e., X is oxygen in Formulae Ithrough VI in Scheme I. Accordingly, the substituted dihydroxyacetophenones, I (where X═O) may be employed as the starting material Inthis preferred embodiment.

In another preferred embodiment a variation of the synthetic procedureas enumerated in Scheme I may be employed to prepare the compounds, VI.Accordingly, in this preferred embodiment, the process for preparingethers, carboxylic acid and sulfonic acid esters, and carbonates of3-diazo-4-oxo-3,4-dihydrocoumarins comprises the steps of:

(a) subjecting a substituted 2,4(5 or 6)-dihydroxy acetophenone to asubstitution conditions in the presence of a compound having theformula:

    R--Z.sub.n,

where

(i) Z is chlorine or bromine;

(ii) n is an integer having a value of 1 to 10; and

(iii) R is selected from the group consisting of:

alkyl of valence n having 1 to 12 carbon atoms,

aralkyl of valence n having 7 to 14 carbon atoms,

aryl of valence n having 6 to 14 carbon atoms,

acyl group having the formula, R'--(CO)_(n) --, where R' is an aliphaticor aromatic group of valence n having 1 to 14 carbon atoms,

alkoxy or aryloxy carbonyl having the formula, R'--(O--CO)_(n) --, whereR' is an aliphatic or aromatic group of valence n having 1 to 14 carbonatoms, and

sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 14carbon atoms;

for a sufficient period of time and under suitable conditions oftemperature and pressure to form the corresponding ether, carboxylicacid or sulfonic acid ester, or carbonate of 2-hydroxyacetophenone;

(b) subjecting said substituted 2-hydroxyacetophenone from step (a) tosuitable addition-cyclization conditions in the presence of a dialkylcarbonate and a catalyst for a sufficient period of time and undersuitable conditions of temperature and pressure to form thecorresponding 4-hydroxy coumarin; and

(c) subjecting said 4-hydroxy coumarin to suitable diazo transferconditions in the presence of a diazo transfer agent for a sufficientperiod of time and under suitable conditions of temperature and pressureto form the corresponding ether, carboxylic acid or sulfonic acid ester,or carbonate of 3-diazo-4-oxo-3,4-dihydrocoumarin.

In this preferred embodiment, utilizing the substituted 2,4(5 or6)-dihydroxy acetophenones (Formula VII, Scheme II) as the startingmaterials, it is believed that the process proceeds as shown in SchemeII below: ##STR11##

In Scheme II, steps (a) through (c) correspond to those steps (a)through (c) referred to in the preferred embodiment as mentioned herein.The step (a), Scheme II of this preferred embodiment may be carried outusing the same procedures of step (d) of Scheme I as mentionedhereinabove. The step (b), Scheme II of this preferred embodiment may becarried out using the same procedures as described for step (b) ofScheme I. Finally, the step (c), Scheme II of this preferred embodimentmay be carried out using the procedures described for step (e) of SchemeI.

This invention is further illustrated by the following examples whichare provided for illustration purposes and in no way limit the scope ofthe present invention.

EXAMPLES (GENERAL)

In the Examples that follow, the following abbreviations are used:

THPE--1',1',1'-Tris(4-hydroxyphenyl)ethane

PDC--Pyridinium dichromate

DHC--Dihydroxycoumarin

THF--Tetrahydrofuran

DMF--Dimethylformamide

TLC--Thin layer chromatography

HPLC--High performance liquid chromatography

IR--Infrared spectroscopy

NMR--Nuclear magnetic resonance spectroscopy, usually of either proton,¹ H; and/or carbon 13, ¹³ C nuclei.

DSC--Differential scanning calorimetry

MS-APCI--Mass spectroscopy-Atmospheric pressure chemical ionization

General Analytical Techniques Used for the Characterization: A varietyof analytical techniques were used to characterize the3,4-dihydrocoumarin compounds of the present invention which includedthe following:

IR: IR spectra of samples were taken using a Nicolet 20SXB FTIRSpectrometer.

NMR: ¹ H and ¹³ C NMR spectra were recorded on a Bruker 400 MHzspectrometer with 5 mm probes at 400 and 100 MHz, respectively.

HPLC: Samples were analyzed with a Hewlett Packard 1090 Series II liquidchromatograph equipped with a 254 nm UV detector and a 150×4.6 mm columnpacked with 5μ Spherisorb C18. The injunction volume was 5 μL. Gradientelution at room temperature and at 1.1 mL/min was carried out withmethanol and 0.1% aqueous acetic acid. The volume concentration ofmethanol in the eluent was increased from 20% to 90 over the firstthirty minutes following injection and was then decreased back to 20% inthe next five minutes.

DSC: A TA 3100 DSC was used to determine the T_(m) of thedihydrocoumarin compounds of this invention. The heating rate wasmaintained at 10° C./minute, generally, over a temperature range of -25°C. to 300° C. The flow rate of nitrogen or air is maintained at 20mL/min.

MS-APCI: A Finnigan SSQ-7000 mass spectrometer was used for allanalyses. While electron ionization mass spectrometry in combinationwith Fourier Transform Infrared (FTIR) Spectroscopy is satisfactory forproviding structural information about smaller size diazo compounds, asthe size of diazo compounds increases, the analysis by electronionization or desorption chemical ionization fails. Atmospheric pressurechemical ionization (APCI) LC/MS operated in the negative ion mode witha mobile phase containing 95% MeOH in water is found very useful tocharacterize large size diazo compounds although they react rapidly withmethanol of the mobile phase.

Example 1 Preparation of 4,8-bis(carboxy)tricyclo 5.2.1.0.²,6 !decane

A 500 mL round-bottom flask was charged with a solution of4,8-bis(hydroxymethyl)tricyclo 5.2.1.0.²,6 !decane (10.1 g, 0.05 moles)in DMF (50 mL). To this solution was added slowly a solution of PDC (149g, 0.4 moles) in DMF (200 mL). The mixture was then stirred at roomtemperature for about 40 hrs. The reaction was monitored by taking smallaliquots of reaction mixture and analyzing by GC and TLC after work-upas follows. About 1 mL of reaction mixture was added to 7 mL of waterand the precipitate formed was filtered and the filtrate was acidifiedwith 1:1 HCl to a pH of 2, which was dissolved in ether for analysis.After complete conversion to diacid as evidenced by GC/TLC, the productwas extracted with a large volume of diethyl ether and the ether layerwas washed with water and dried over MgSO₄. The white solid acid wasisolated using a rotary evaporator; yield, 5.2 g, (44%). The product wascharacterized by IR and NMR: IR (KBr) 3200-3600 cm⁻¹ (OH group), 1690cm⁻¹ (C═O); ¹³ C NMR (DMSO-d₆): five observed peaks due to isomers at179-180 ppm (C═O).

Example 2 Preparation of 4,8-bis(chlorocarbonyl)tricyclo 5.2.1.0.²,6!decane

The diacid prepared in accordance with Example 1 was converted to diacidchloride as follows. A 3-neck round-bottom flask equipped with acondenser and a stirrer was charged with of 4,8-bis(carboxy)tricyclo5.2.1.0.²,6 !decane (2 g). Thionyl chloride (5.2 mL, 70 mmol) was addedslowly at room temperature to under an atmosphere of N₂. After theaddition was complete, the reaction mixture was heated to 85° C. in anoil bath and refluxed for 3 hours. Excess thionyl chloride wasevaporated to obtain the desired acid chloride; yield 79%. The productwas characterized by IR, MS, and NMR: IR (Film), 1780 & 1700 cm⁻¹ (C═O);APCI (-ve ion mode) flow injection (60:40 acetonitrile:H₂ O (HOAc) MSm/z calcd for C₁₂ H₂₄ Cl₂ O₂ (M--H) 259, 261; ¹³ C NMR (CDCl₃) 175.7,175.9, 176.1, 176.3, 176.4 (C═O).

Example 3 Preparation of 4,8-bis(chloromethyl)tricyclo 5.2.1.0.²,6!decane

A 3-neck 100 mL round-bottom flask was charged with a solution of4,8-bis(hydroxymethyl)tricyclo 5.2.1.0.²,6 !decane (10.2 g, 50 mmol) inDMF (10 mL) and pyridine (2 mL). To this solution was added thionylchloride (14.6 mL, 0.2 moles) slowly using an addition funnel at 5° C.After the addition was complete, the flask was heated to reflux using anoil bath for 6 hrs (ca 160° C.). The reaction mixture was cooled, mixedwith ice water (1:1), and the product was extracted with large mounts ofether. The ether layer was washed with saturated NaHCO₃ solution, waterand dried over MgSO₄. The product was isolated by evaporation of ether;yield 50%. The product was characterized by NMR, GC, and GC/MS.

Example 4 Preparation of 4-benzyloxy-2-hydroxy-acetophenone

A 500 mL 3-neck round-bottom flask equipped with a mechanical stirrer,condenser and a thermocouple was charged with acetone (150 mL),2,4-dihydroxyacetophenone (15.2 g, 0.1 mol), benzyl chloride (16.5 g,0.13 mol), potassium iodide (1.7 g, 0.01 mol) and potassium carbonate(15.2 g, 0.11 mol). The reaction mixture was heated to reflux for ˜3 hrsunder an atmosphere of N₂. The completion of the reaction was monitoredby GC and HPLC. The mixture was filtered through a frit and the filteredcake (19.8 g) was washed with 150 mL of acetone. The filtrate wasevaporated to dryness. The orange solid was recrystallized frommethanol; yield 78.5%.

Example 5 Preparation of 7-Benzyloxy-4-hydroxy-coumarin

4-Benzyloxy-2-hydroxy-acetophenone (20 g, 0.0825 mol), prepared inaccordance with Example 4, was dissolved in 150 mL of toluene. To thissolution was added diethyl carbonate (25.3 g, 0.21 mol) and the entirecontents taken in a beaker was heated while stirring to dissolve thestarting material. This solution was then taken in an addition funneland was added at a rate of 7-8 mL/min (addition time=1.5 hrs) to asuspension of sodium hydride (4.3 g, 10.1 mol) in toluene (100 mL) takenin a 500 mL 4-neck flask equipped with a mechanical stirrer, adistillation apparatus (double jacketed-splitter heads) with acondenser, a thermocouple, and a thermometer to read the temperature ofthe distillate under N₂ atmosphere. The reaction flask was heated to110°-115° C. with a heating mantle during the addition. Ethanol producedduring this reaction is removed as an azeotrope with toluene. Additionaltoluene was added through the addition funnel to have enough of toluenein the reaction flask. The reaction mixture was refluxed for ˜5 hrs tocomplete the reaction. The contents of the reaction flask weretransferred to a separatory funnel and 400 mL of distilled water wasadded to separate into two phases. The aqueous layer was acidified to pH2.0 with 1:1 dil. HCl and filtered under vacuum. The crude product wasrecrystallized from hot methanol; yield 84%.

Example 6 Preparation of 4,7-Dihydroxy-coumarin

A 300 cc autoclave was charged with 7-benzyloxy-4-hydroxycoumarin (3 g,3.7 mmol), prepared in accordance with Example 5, 5% Pd on carbon (0.18g) and 85 mL of methanol and the autoclave was purged with N₂. Theautoclave was pressurized with H₂ to a pressure of about 100 psi andmaintained at that pressure. The exothermic reaction was carried out at˜50° C. for ˜2hrs. After the completion of hydrogenolysis, the reactorwas flushed with N₂ and the contents were transferred into a beakerusing a long pipet. The mixture containing Pd/C was dried over MgSO₄ andfiltered through a frit. The filtrate was evaporated to dryness andfinally dried overnight at 45° C. The purity of the material asdetermined by LC was 95%; yield ˜90%. The product was characterized byNMR.

Examples 7-8

Example 4 was substantially repeated in Examples 7-8 with the exceptionthat the materials and the amounts used were as set forth below:

    ______________________________________                                                     Amounts                                                          Materials      Example 7    Example 8                                         ______________________________________                                        2,5-Dihydroxyacetophenone                                                                    15.2 g  (0.1 mol)                                                                              --                                            2,6-Dihydroxyacetophenone                                                                    --               15.2 g                                                                              (0.1 mol)                               Benzyl chloride                                                                              16.5 g  (0.13 mol                                                                              16.5 g                                                                              (0.13 mol)                              Potassium iodide                                                                             1.66 g  (0.01 mol)                                                                             1.66 g                                                                              (0.01 mol)                              Potassium carbonate                                                                          15.2 g  (0.11 mol)                                                                             15.2 g                                                                              (0.11 mol)                              The product formed and its                                                    yield were as follows:                                                        5-Benzyloxy-2-hydroxy-                                                                       22.0 g  (91%)    --                                            acetophenone                                                                  6-Benzyloxy-2-hydroxy-                                                                       --               10.5 g                                                                              (43.5%)                                 acetophenone                                                                  ______________________________________                                    

Examples 9-10

Example 5 was substantially repeated in Examples 9-10 with the exceptionthat the materials and the amounts used were as set forth below:

    ______________________________________                                                    Amounts                                                           Materials     Example 9    Example 10                                         ______________________________________                                        5-Benzyloxy-2-hydroxy-                                                                      60.0 g  (0.25 mol)                                                                             --                                             acetophenone                                                                  (from Example 7)                                                              6-Benzyloxy-2-hydroxy-                                                                      --               19 g  (0.0784 mol)                             acetophenone                                                                  (from Example 8)                                                              Diethyl carbonate                                                                           75.9 g  (0.63 mol)                                                                             25.3 g                                                                              (0.21 mol)                               Sodium hydride                                                                              12.84 g (0.32 mol)                                                                             4.28 g                                                                              (0.11 mol)                               The product formed and its                                                    yield were as follows:                                                        6-benzyloxy-4-hydroxy-                                                                      47.6 g  (71.6%)  --                                             coumarin                                                                      5-benzyloxy-4-hydroxy-                                                                      --               7.64 g                                                                              (36.3%)                                  coumarin                                                                      ______________________________________                                    

Examples 11-12

Example 6 was substantially repeated in Examples 11-12 with theexception that the solvent used was THF in example 12 instead ofmethanol and the materials and the amounts used were as set forth below:

    ______________________________________                                                   Amounts                                                            Materials    Example 11    Example 12                                         ______________________________________                                        6-benzyloxy-4-hydroxy-                                                                     11.9 g  (0.044 mol)                                                                             --                                             coumarin                                                                      (from Example 9)                                                              5-benzyloxy-4-hydroxy-                                                                     --                1 g   (3.7 mmol)                               coumarin                                                                      (from Example 10)                                                             5% Pd on C   0.7 g             0.06 g                                         The product formed and                                                        its yield were as follows:                                                    4,6-Dihydroxy-coumarin                                                                     5 g     (65%)                                                    4,5-Dihydroxy-coumarin                                                                     --                0.6 g (95%)                                    ______________________________________                                    

Example 13 Preparation of4,8-bis(4-hydroxy-7-oxy-carbonyl-coumarin)tricyclo 5.2.1.0.²,6 !-decane

A 50 mL 3 neck round-bottom flask equipped with a magnetic stirrer, aseptum, an addition funnel and a N₂ outlet was charged with a solutionof 4,7-dihydroxycoumarin prepared in accordance with Example 6 (1.0 g,5.6 mmol) in THF (15 mL) and triethylamine (1.6 mL). To this solutionwas added dropwise a solution of 4,8-bis(chlorocarbonyl)-tricyclo5.2.1.0.²,6 !decane prepared in accordance with Example 2 (0.75 g, 2.8mmol) in dry THF (5 mL). The solution mined brown after addition of theacid chloride and the solution was stirred at room temperature for 24hrs. The completion of the reaction was monitored by HPLC. Acetone (20mL) was then added to this solution and the insoluble materials werefiltered. The filtrate was rotavaporized to obtain a white solid; yieldis quantitative. The product was characterized by NMR: ¹³ C NMR (100 MHzin DMSO-d6)): 173.9, 170.8, 163.5, 154.5, 152.6, 124.8, 118.0, 116.6,109.3, 87.2. DSC, m.pt. 175° C.

Example 14 Preparation of4,8-bis(4-hydroxy-6-oxy-carbonyl-coumarin)tricyclo 5.2.1.0.²,6 !decane

Example 13 was substantially repeated in Example 14 with the exceptionof the materials and amounts used as set forth below:

    ______________________________________                                        Materials                 Amount                                              ______________________________________                                        4,6-dihydroxycoumarin     5 g, 28 mmol                                        (prepared in accordance with Example 11)                                      THF                       75 mL                                               Triethylamine             8 mL                                                4,8-bis(chlorocarbonyl)-tricyclo 5.2.1.0..sup.2,6 !decane                                               4.8 g, 18 mmol                                      (prepared in accordance with Example 2)                                       THF                       25 mL                                               ______________________________________                                    

The product was obtained in quantitative yields and characterized byNMR.

Example 15 Preparation of4,8-bis(4-hydroxy-5-oxy-carbonyl-coumarin)tricyclo 5.2.1.0.²,6 !decane

Example 13 was substantially repeated in Example 14 with the exceptionof the materials and amounts used as set forth below:

    ______________________________________                                        Materials                Amount                                               ______________________________________                                        4,5-dihydroxycoumarin    0.7 g, 3.6 mmol                                      (prepared in accordance with Example 12)                                      THF                      15 mL                                                Triethylamine            1.6 mL                                               4,8-bis(chlorocarbonyl)-tricyclo 5.2.1.0..sup.2,6 !decane                                              0.5 g, 2 mmol                                        (prepared in accordance with Example 2)                                       THF                      5 mL                                                 ______________________________________                                    

The product was obtained in quantitative yields and characterized by NMRand MS (APCI).

Example 16 Preparation of 3-diazo-4-oxo-7-benzyloxy-3,4-dihydrocoumarin

A solution of7-benzyloxy-4-hydroxy coumarin (2.5 g, 9.3 mmol; preparedin accordance with Example 5) in anhydrous THF (40 mL) was mixed withtriethylamine (0.9 g, 9 mmol) taken in a 100 mL 3-neck round-bottomflask under an atmosphere of N₂. A solution of p-toluenesulfonyl azide(2.8 g, 14 mmol) in dry THF (20 mL) was added dropwise through anaddition funnel. The mixture was stirred at room temperature for 3 hrs.The color of the solution turned orange. The solvent was rotaryevaporated and the product was taken in CH₂ Cl₂ and washed with water (3times). Petroleum ether (twice the volume) was added to the solution andthe solid precipitate was filtered with a frit and dried at 45° C. Theproduct was recrystallized using CH₂ Cl₂ ; yield 90%. The product wascharacterized by NMR: ¹³ C NMR (100 MHz, CD₂ Cl₂): 173.3, 165.4, 158.7,156.0, 136.0, 129.1, 128.8, 128.0, 127.6, 113.9, 113.0, 103.0, 75.7,71.2; DSC - m. pt. 191° C. followed by decomposition; IR (KBr): 2182,2154, 1717, 1647, 1605 cm⁻¹ ; MS(APCI): (M+H), 295 (base peak).

Example 17 Preparation of 3-diazo-4-oxo-5-benzyloxy-3,4-dihydrocoumarin

Example 16 was substantially repeated in Example 17 with the exceptionof the materials and amounts used as set forth below:

    ______________________________________                                        Materials              Amount                                                 ______________________________________                                        5-Benzyloxy-4-hydroxy-coumarin                                                                       1 g, 3.7 mmol                                          (prepared in accordance with Example 10)                                      THF                    20 mL                                                  Triethylamine          0.4 g, 3.7 mmol                                        p-toluenesulfonyl azide                                                                              0.8 g, 4 mmol                                          THF                    5 mL                                                   ______________________________________                                    

After 3 hrs of reaction at room temperature, the solvent was evaporatedand the product was placed in a freezer during which time the productcrystallized. The crystals were removed using a frit; yield 56%. Theproduct was characterized by NMR and IR: ¹³ C NMR (100 MHz): 172.8,159.1, 158.3, 156.0, 136.6, 136.3, 128.9, 128.3, 127.3, 110.5, 109.9,109.6, 77.0, 71.3; IR(KBr): C═N₂ at 2124 cm⁻¹ ; C═O 1730 cm⁻¹ ; DSC - m.pt. 149° C. followed by a significant exothermic peak at ˜200° C; MS(APCI): +ve ion mode (energy induced dissociation) --M+H at 295, M+H--N₂at 267; -ve ion mode, M₂ --2N₂ =532 (base peak).

Example 18 Preparation of4,8-bis(3-diazo-4-oxo-7-oxy-carbonyl-3,4-dihydrocoumarin)tricyclo5.2.1.0.²,6 !-decane

Example 16 was substantially repeated in Example 18 with the exceptionof the materials and amounts used as set forth below:

    ______________________________________                                        Materials                Amount                                               ______________________________________                                        4,8-bis(4-hydroxy-7-oxy-carbonyl-3,4-dihydro-                                                          0.5 g, 0.9 mmol                                      coumarin)tricyclo 5.2.1.0..sup.2,6 !-decane                                   (from Example 13)                                                             THF                      30 mL                                                Triethylamine            0.3 mL, 2 mmol                                       p-Toluenesulfonyl azide  0.4 g, 2 mmol                                        dry THF                  10 mL                                                ______________________________________                                    

The product was characterized by NMR, IR, and MS: ¹³ C NMR (100 MHz inDMSO-d₆): 173.4, 173.0, 157.7, 154.1, 129.2, 125.6, 119.3, 116.5, 111.4,76.9; MS (APCI) -ve ion mode; M--2N₂ +2MeOH--H=603.2, M--N₂+MeOH--H=599; FTIR (KBr): 2140 cm⁻¹ (C═N₂), 1732 cm⁻¹ (C═O).

Example 19 Preparation of 4,8-bis-(3-diazo-4-oxo-5-oxy-carbonyl-3,4-dihydrocoumarin)tricyclo 5.2.1.0.²,6!-decane

Example 16 was substantially repeated in Example 18 with the exceptionof the materials and amounts used as set forth below:

    ______________________________________                                        Materials                Amount                                               ______________________________________                                        4,8-bis(4-hydroxy-5-oxy-carbonyl-coumarin)-                                                            1.1 g, 2 mmol                                        tricyclo 5.2.1.0..sup.2.6 !-decane (from Example 15)                          THF                      30 mL                                                Cesium carbonate         1.3 g, 4 mmol                                        p-Toluenesulfonyl azide  0.8 g,4 mmol                                         dry THF                  10 mL                                                ______________________________________                                    

The reaction mixture was filtered after stirring for about 10 hrs atroom temperature, and the filtrate was chromatographed on silica gelusing ethyl acetate/hexane solvent mixture. Polarity of the eluent wasincreased by adding methanol to ethyl acetate. The fractions werechecked by TLC and characterized by HPLC, MR, IR and MS: IR (KBr): 2154cm⁻¹ (C═N₂), and 1732 cm⁻¹ (C═O); MS (APCI): M--N₂ +MeOH--H=599.2;M--2N₂ +2 MeOH--H=603.2; ¹³ C NMR: 77.6 (C═N₂).

Example 20 Preparation of4,8-bis(3-diazo-4-oxo-6-oxy-carbonyl-3,4-dihydrocoumarin)tricyclo5.2.1.0.²,6 !-decane

Example 16 was substantially repeated in Example 20 with the exceptionthat the base used was cesium carbonate (4.2 g) and dry dichloromethane(95 mL) was used as the co-solvent. Various other materials and amountsused in Example 20 are as set forth below:

    ______________________________________                                        Materials                Amount                                               ______________________________________                                        4,8-bis(4-hydroxy-6-oxy-carbonyl-coumarin)-                                                            3.5 g, 6.4 mmol                                      tricyclo 5.2.1.0..sup.2,6 !-decane (from Example 14)                          CH.sub.2 CL.sub.2        95 mL                                                Cesium Carbonate         4.2 g, 13 mmol                                       p-Toluenesulfonyl azide  2.5 g, 13 mmol                                       dry THF                  20 mL                                                ______________________________________                                    

Example 21 Preparation of1',1',1'-tris-(4-(4-hydroxy-7-coumarincarbanato)phenyl)ethane

This Example illustrates the preparation of carbonates of thephotoactive compounds of the present invention. First thetris-chloroorthoformate of THPE was synthesized as follows. To a 100 mL3-neck flask equipped with a 25 mL addition funnel, N₂ outlet and aseptam was added solid triphosgene (1 g) inside a glove box. THF (3 mL)was added to the flask under N₂ through the septum to dissolvetriphosgene and the flask was placed in an ice bath. Triethylamine (1.4mL, 10 mmol) dissolved in THF (4 mL) was then added slowly to the flaskthrough the septum. A white precipitate appeared. THPE (1.1 g, 3.8 mmol)dissolved in dry THF (7 mL) was added slowly to the flask through anaddition funnel over a period of 45 minutes. The reaction was stirred atroom temperature for 5 hrs and filtered using a frit and rinsed with THFand the filtrate was taken into an addition funnel under N₂ atmosphere.

A solution of 4,7-DHC (1 g, 5.6 mmol), prepared in accordance withExample 6, in THF (20 mL) was taken in another 100 mL 3 -neck flaskunder N₂ atmosphere. To this solution was added triethylamine (1.7 mL).The THPE-tris-chloroorthoformate as prepared above was slowly added to4,7-DHC solution at room temperature in about 14-16 hrs. The reactionmixture was then filtered through a frit and the residue was washed with30 to 40 mL of HPLC grade acetone. The combined filtrates wereevaporated to dryness; yield 1.6 g. The product was characterized byNMR.

Although the invention has been illustrated by certain of the precedingexamples, it is not to be construed as being limited thereby; butrather, the invention encompasses the generic area as hereinbeforedisclosed. Various modifications and embodiments can be made withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. A process for preparing ethers, carboxylic acidand sulfonic acid esters, and carbonates of3-diazo-2,4-dioxo-benzo-heterocyclic compounds comprising the stepsof:(a) subjecting a substituted hydroxy acetophenone to a substitutionreaction in the presence of a suitable protecting group for a sufficientperiod of time and under suitable conditions of temperature and pressureto form the corresponding hydroxy-protected-acetophenone; (b) subjectingsaid hydroxy-protected-acetophenone to suitable addition-cyclizationconditions in the presence of a dialkyl carbonate and a catalyst for asufficient period of time and under suitable conditions of temperatureand pressure to form the corresponding benzo-heterocyclic compoundcontaining a β-keto-enol group; (c) subjecting said heterocycliccompound to suitable deprotection conditions for a sufficient period oftime and under suitable conditions of temperature and pressure to formthe corresponding hydroxy-benzo-heterocyclic compound containing aβ-keto-enol group; (d) subjecting said hydroxy-benzo-heterocycliccompound to suitable substitution conditions in the presence of acompound having the formula:

    R--Z.sub.n,

where (i) Z is chlorine, or bromine; (ii) n is an integer having a valueof 1 to 10; and (iii) R is selected from the group consisting of:alkylof valence n having 1 to 12 carbon atoms, aralkyl of valence n having 7to 14 carbon atoms, aryl of valence n having 6 to 14 carbon atoms, acylgroup having the formula, R'--(CO)_(n) --, where R' is an aliphatic oraromatic group of valence n having 1 to 14 carbon atoms, alkoxy oraryloxy carbonyl having the formula, R'--(O--CO)_(n) --, where R' is analiphatic or aromatic group of valence n having 1 to 14 carbon atoms,and sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 14carbon atoms;for a sufficient period of time and under suitableconditions of temperature and pressure to form the corresponding ether,carboxylic acid or sulfonic acid ester, or carbonate ofbenzo-heterocyclic compound containing a β-keto-enol group; and (e)subjecting said β-keto-enol compound from step (d) to suitable diazotransfer conditions in the presence of a diazo transfer agent for asufficient period of time and under suitable conditions of temperatureand pressure to form the corresponding ether, carboxylic acid orsulfonic acid ester, or carbonate of3-diazo-2,4-dioxo-benzo-heterocyclic compound.
 2. The process as setforth in claim 1 wherein said substituted hydroxy acetophenone has theformula: ##STR12## wherein: (a) X is either oxygen or sulfur; and(b) R₁,R₂, and R₃ are the same or different and are independently selected fromthe group consisting of:hydrogen, fluorine, chlorine, bromine, oriodine, linear or branched alkyl and fluoroalkyl groups having theformula C_(n) H_(x) F_(y), where n is an integer from 1 to 8, x and yare integers from 0 to 2n+1, and the sum of x and y is 2n+1;, arylhaving 6 to 10 carbon atoms, aralkyl having 7 to 10 carbon atoms, alkoxyhaving 1 to 8 carbon atoms, aryloxy having 6 to 10 carbon atoms, andaralkyloxy having 7 to 10 carbon atoms.
 3. The process as set forth inclaim 1 wherein said ethers, carboxylic acid and sulfonic acid esters,and carbonates of 3-diazo-2,4-dioxo-benzo-heterocyclic compounds havethe formula: ##STR13## wherein: (a) X is either oxygen or sulfur;(b) Ris selected from the group consisting of:hydrogen, alkyl of valence nhaving 1 to 12 carbon atoms, aralkyl of valence n having 7 to 14 carbonatoms, aryl of valence n having 6 to 14 carbon atoms, acyl group havingthe formula, R'--(CO)_(n) --, where R' is an aliphatic or aromatic groupof valence n having 1 to 14 carbon atoms, alkoxy or aryloxy carbonylhaving the formula, R'--(O--CO)_(n) --, where R' is an aliphatic oraromatic group of valence n having 1 to 14 carbon atoms, andsulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 14carbon atoms; (c) R₁, R₂, and R₃ are the same or different and areindependently selected from the group consisting of:hydrogen, fluorine,chlorine, bromine, or iodine, linear or branched alkyl and fluoroalkylgroups having the formula C_(n) H_(x) F_(y), where n is an integer from1 to 8, x and y are integers from 0 to 2n+1, and the sum of x and y is2n+1;, aryl having 6 to 10 carbon atoms, aralkyl having 7 to 10 carbonatoms, alkoxy having 1 to 8 carbon atoms, aryloxy having 6 to 10 carbonatoms, and aralkyloxy having 7 to 10 carbon atoms; and (d) n is aninteger having a value of 1 to
 10. 4. The process as set forth in claim3 wherein X is sulfur.
 5. The process as set forth in claim 1 wherein instep (a) the temperature is from about 50° C. to about 180° C. andpressure is atmospheric; in step (b) the temperature is from about 80°C. to about 200° C. and pressure is atmospheric; in step (c) thetemperature is from about 20° C. to about 80° C. and pressure is eitheratmospheric or superatmospheric; in step (d) the temperature is fromabout 10° C. to about 180° C. and pressure is atmospheric; and in step(e) the temperature is from about 10° C. to about 50° C. and pressure isatmospheric.
 6. A process for preparing ethers, carboxylic acid andsulfonic acid esters, and carbonates of 3-diazo-4-oxo-coumarinscomprising the steps of:(a) subjecting a substituted 2,4(5 or6)-dihydroxy acetophenone to a substitution reaction in the presence ofa suitable protecting group and a catalyst for a sufficient period oftime and under suitable conditions of temperature and pressure to formthe corresponding 4(5 or 6)-hydroxy-protected-2-hydroxyacetophenone; (b)subjecting said hydroxy-protected hydroxyacetophenone to suitableaddition-cyclization conditions in the presence of a dialkyl carbonateand a catalyst for a sufficient period of time and under suitableconditions of temperature and pressure to form the corresponding4-hydroxy coumarin; (c) subjecting said 4-hydroxy coumarin to suitabledeprotection conditions for a sufficient period of time and undersuitable conditions of temperature and pressure to form thecorresponding dihydroxy coumarin; (d) subjecting said dihydroxy coumarinto suitable substitution conditions in the presence of a compound havingthe formula:

    R--Z.sub.n,

where (i) Z is chlorine or bromine; (ii) n is an integer having a valueof 1 to 10; and (iii) R is selected from the group consisting of:alkylof valence n having 1 to 12 carbon atoms, aralkyl of valence n having 7to 14 carbon atoms, aryl of valence n having 6 to 14 carbon atoms, acylgroup having the formula, R'--(CO)_(n) --, where R' is an aliphatic oraromatic group of valence n having 1 to 14 carbon atoms, alkoxy oraryloxy carbonyl having the formula, R'--(O--CO)_(n) --, where R' is analiphatic or aromatic group of valence n having 1 to 14 carbon atoms,and sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 14carbon atoms;for a sufficient period of time and under suitableconditions of temperature and pressure to form the corresponding ether,carboxylic acid or sulfonic acid ester, or carbonate of dihydroxycoumarin; and (e) subjecting said dihydroxy coumarin compound from step(d) to suitable diazo transfer conditions in the presence of a diazotransfer agent for a sufficient period of time and under suitableconditions of temperature and pressure to form the corresponding ether,carboxylic acid or sulfonic acid ester, or carbonate of3-diazo-4-oxo-coumarin.
 7. The process as set forth in claim 6 whereinsaid substituted 2,4(5 or 6)-dihydroxy acetophenone has the formula:##STR14## wherein R₁, R₂, and R₃ are the same or different and areindependently selected from the group consisting of:hydrogen, fluorine,chlorine, bromine, or iodine, linear or branched alkyl and fluoroalkylgroups having the formula C_(n) H_(x) F_(y), where n is an integer from1 to 8, x and y are integers from 0 to 2n+1, and the sum of x and y is2n+1;, aryl having 6 to 10 carbon atoms, aralkyl having 7 to 10 carbonatoms, alkoxy having 1 to 8 carbon atoms, aryloxy having 6 to 10 carbonatoms, and aralkyloxy having 7 to 10 carbon atoms.
 8. The process as setforth in claim 6 wherein said ether, carboxylic acid or sulfonic acidester, or carbonate of 3-diazo-4-oxo-coumarin has the formula: ##STR15##wherein: (a) R is selected from the group consisting of:alkyl of valencen having 1 to 12 carbon atoms, aralkyl of valence n having 7 to 14carbon atoms, aryl of valence n having 6 to 14 carbon atoms, acyl grouphaving the formula, R'--(CO)_(n) --, where R' is an aliphatic oraromatic group of valence n having 1 to 14 carbon atoms, and n is aninteger having a value of 1 to 6, alkoxy or aryloxy carbonyl having theformula, R'--(O--CO)_(n) --, where R' is an aliphatic or aromatic groupof valence n having 1 to 14 carbon atoms, and sulfonylalkyl orsulfonylaryl having the formula, R'--(SO₂)_(n) --, where R' is analiphatic or aromatic group of valence n having 1 to 14 carbon atoms;(b) R₁, R₂, and R₃ are the same or different and are independentlyselected from the group consisting of:hydrogen, fluorine, chlorine,bromine, or iodine, linear or branched alkyl and fluoroalkyl groupshaving the formula C_(n) H_(x) F_(y), where n is an integer from 1 to 8,x and y are integers from 0 to 2n+1, and the sum of x and y is 2n+1;,aryl having 6 to 10 carbon atoms, aralkyl having 7 to 10 carbon atoms,alkoxy having 1 to 8 carbon atoms, aryloxy having 6 to 10 carbon atoms,and aralkyloxy having 7 to 10 carbon atoms; and (c) n is an integerhaving a value of 1 to
 10. 9. The process as set forth in claim 8wherein R₁ to R₃ are hydrogen.
 10. The process as set forth in claim 6wherein in step (a) the temperature is from about 50° C. to about 100°C. and pressure is atmospheric; in step (b) the temperature is fromabout 80° C. to about 150° C. and pressure is atmospheric; in step (c)the temperature is from about 30° C. to about 60° C. and pressure issuperatmospheric; in step (d) the temperature is from about 10° C. toabout 100° C. and pressure is atmospheric; and in step (e) thetemperature is from about 20° C. to about 40° C. and pressure isatmospheric.
 11. The process as set forth in claim 6 wherein saidprotecting group is selected from the group consisting of benzyl,trimethylsilyl, tert-butyldimethylsilyl, 2-tetrahydropyranyl, andtert-butyloxycarbonyl.
 12. The process as set forth in claim 11 whereinsaid protecting group is benzyl.
 13. The process as set forth in claim 6wherein said dialkyl carbonate is diethyl carbonate.
 14. The process asset forth in claim 6 wherein said diazo transfer agent isp-toluenesulfonyl azide.
 15. A process for preparing ethers, carboxylicacid and sulfonic acid esters, and carbonates of 3-diazo-4-oxo-coumarinscomprising the steps of:(a) subjecting a substituted 2,4(5 or6)-dihydroxy acetophenone to a substitution conditions in the presenceof a compound having the formula:

    R--Z.sub.n,

where (i) Z is chlorine or bromine; (ii) n is an integer having a valueof 1 to 10; and (iii) R is selected from the group consisting of:alkylof valence n having 1 to 12 carbon atoms, aralkyl of valence n having 7to 14 carbon atoms, aryl of valence n having 6 to 14 carbon atoms, acylgroup having the formula, R'--(CO)_(n) --, where R' is an aliphatic oraromatic group of valence n having 1 to 14 carbon atoms, alkoxy oraryloxy carbonyl having the formula, R'--(O--CO)_(n) --, where R' is analiphatic or aromatic group of valence n having 1 to 14 carbon atoms,and sulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 14carbon atoms; for a sufficient period of time and under suitableconditions of temperature and pressure to form the corresponding ether,carboxylic acid or sulfonic acid ester, or carbonate of2-hydroxyacetophenone; (b) subjecting said substituted2-hydroxyacetophenone from step (a) to suitable addition-cyclizationconditions in the presence of a dialkyl carbonate and a catalyst for asufficient period of time and under suitable conditions of temperatureand pressure to form the corresponding 4-hydroxy coumarin; and (c)subjecting said 4-hydroxy coumarin to suitable diazo transfer conditionsin the presence of a diazo transfer agent for a sufficient period oftime and under suitable conditions of temperature and pressure to formthe corresponding ether, carboxylic acid or sulfonic acid ester, orcarbonate of 3-diazo-4-oxo-coumarin.
 16. The process as set forth inclaim 15 wherein said substituted 2,4(5 or 6)-dihydroxy acetophenone hasthe formula: ##STR16## wherein R₁, R₂, and R₃ are the same or differentand are independently selected from the group consisting of:hydrogen,fluorine, chlorine, bromine, or iodine, linear or branched alkyl andfluoroalkyl groups having the formula C_(n) H_(x) F_(y), where n is aninteger from 1 to 8, x and y are integers from 0 to 2n+1, and the sum ofx and y is 2n+1;, aryl having 6 to 10 carbon atoms, aralkyl having 7 to10 carbon atoms, alkoxy having 1 to 8 carbon atoms, aryloxy having 6 to10 carbon atoms, and aralkyloxy having 7 to 10 carbon atoms.
 17. Theprocess as set forth in claim 15 wherein said ether, carboxylic acid orsulfonic acid ester, or carbonate of 3-diazo-4-oxo-coumarin has theformula: ##STR17## wherein: (a) R is selected from the group consistingof:alkyl of valence n having 1 to 12 carbon atoms, aralkyl of valence nhaving 7 to 14 carbon atoms, aryl of valence n having 6 to 14 carbonatoms, acyl group having the formula, R'--(CO)_(n) --, where R' is analiphatic or aromatic group of valence n having 1 to 14 carbon atoms,and n is an integer having a value of 1 to 6, alkoxy or aryloxy carbonylhaving the formula, R'--(O--CO)_(n) --, where R' is an aliphatic oraromatic group of valence n having 1 to 14 carbon atoms, andsulfonylalkyl or sulfonylaryl having the formula, R'--(SO₂)_(n) --,where R' is an aliphatic or aromatic group of valence n having 1 to 14carbon atoms; (b) R₁, R₂, and R₃ are the same or different and areindependently selected from the group consisting of:hydrogen, fluorine,chlorine, bromine, or iodine, linear or branched alkyl and fluoroalkylgroups having the formula C_(n) H_(x) F_(y), where n is an integer from1 to 8, x and y are integers from 0 to 2n+1, and the sum of x and y is2n+1;, aryl having 6 to 10 carbon atoms, aralkyl having 7 to 10 carbonatoms, alkoxy having 1 to 8 carbon atoms, aryloxy having 6 to 10 carbonatoms, and aralkyloxy having 7 to 10 carbon atoms; and (c) n is aninteger having a value of 1 to
 6. 18. The process as set forth in claim17 wherein R₁ to R₃ are hydrogen.
 19. The process as set forth in claim15 wherein in step (a) the temperature is from about 50° C. to about100° C. and pressure is atmospheric; in step (b) the temperature is fromabout 80° C. to about 150° C. and pressure is atmospheric; and in step(c) the temperature is from about 20° C. to about 40° C. and pressure isatmospheric.
 20. The process as set forth in claim 15 wherein saiddialkyl carbonate is diethyl carbonate.
 21. The process as set forth inclaim 15 wherein said diazo transfer agent is p-toluenesulfonyl azide.